/**
 * @license Copyright (c) 2003-2023, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * Enables autoformatting mechanism for a given {@link module:core/editor/editor~Editor}.
 *
 * It formats the matched text by applying the given model attribute or by running the provided formatting callback.
 * On every {@link module:engine/model/document~Document#event:change:data data change} in the model document
 * the autoformatting engine checks the text on the left of the selection
 * and executes the provided action if the text matches given criteria (regular expression or callback).
 *
 * @param editor The editor instance.
 * @param plugin The autoformat plugin instance.
 * @param testRegexpOrCallback The regular expression or callback to execute on text.
 * Provided regular expression *must* have three capture groups. The first and the third capture group
 * should match opening and closing delimiters. The second capture group should match the text to format.
 *
 * ```ts
 * // Matches the `**bold text**` pattern.
 * // There are three capturing groups:
 * // - The first to match the starting `**` delimiter.
 * // - The second to match the text to format.
 * // - The third to match the ending `**` delimiter.
 * inlineAutoformatEditing( editor, plugin, /(\*\*)([^\*]+?)(\*\*)$/g, formatCallback );
 * ```
 *
 * When a function is provided instead of the regular expression, it will be executed with the text to match as a parameter.
 * The function should return proper "ranges" to delete and format.
 *
 * ```ts
 * {
 * 	remove: [
 * 		[ 0, 1 ],	// Remove the first letter from the given text.
 * 		[ 5, 6 ]	// Remove the 6th letter from the given text.
 * 	],
 * 	format: [
 * 		[ 1, 5 ]	// Format all letters from 2nd to 5th.
 * 	]
 * }
 * ```
 *
 * @param formatCallback A callback to apply actual formatting.
 * It should return `false` if changes should not be applied (e.g. if a command is disabled).
 *
 * ```ts
 * inlineAutoformatEditing( editor, plugin, /(\*\*)([^\*]+?)(\*\*)$/g, ( writer, rangesToFormat ) => {
 * 	const command = editor.commands.get( 'bold' );
 *
 * 	if ( !command.isEnabled ) {
 * 		return false;
 * 	}
 *
 * 	const validRanges = editor.model.schema.getValidRanges( rangesToFormat, 'bold' );
 *
 * 	for ( let range of validRanges ) {
 * 		writer.setAttribute( 'bold', true, range );
 * 	}
 * } );
 * ```
 */
export default function inlineAutoformatEditing(editor, plugin, testRegexpOrCallback, formatCallback) {
    let regExp;
    let testCallback;
    if (testRegexpOrCallback instanceof RegExp) {
        regExp = testRegexpOrCallback;
    }
    else {
        testCallback = testRegexpOrCallback;
    }
    // A test callback run on changed text.
    testCallback = testCallback || (text => {
        let result;
        const remove = [];
        const format = [];
        while ((result = regExp.exec(text)) !== null) {
            // There should be full match and 3 capture groups.
            if (result && result.length < 4) {
                break;
            }
            let { index, '1': leftDel, '2': content, '3': rightDel } = result;
            // Real matched string - there might be some non-capturing groups so we need to recalculate starting index.
            const found = leftDel + content + rightDel;
            index += result[0].length - found.length;
            // Start and End offsets of delimiters to remove.
            const delStart = [
                index,
                index + leftDel.length
            ];
            const delEnd = [
                index + leftDel.length + content.length,
                index + leftDel.length + content.length + rightDel.length
            ];
            remove.push(delStart);
            remove.push(delEnd);
            format.push([index + leftDel.length, index + leftDel.length + content.length]);
        }
        return {
            remove,
            format
        };
    });
    editor.model.document.on('change:data', (evt, batch) => {
        if (batch.isUndo || !batch.isLocal || !plugin.isEnabled) {
            return;
        }
        const model = editor.model;
        const selection = model.document.selection;
        // Do nothing if selection is not collapsed.
        if (!selection.isCollapsed) {
            return;
        }
        const changes = Array.from(model.document.differ.getChanges());
        const entry = changes[0];
        // Typing is represented by only a single change.
        if (changes.length != 1 || entry.type !== 'insert' || entry.name != '$text' || entry.length != 1) {
            return;
        }
        const focus = selection.focus;
        const block = focus.parent;
        const { text, range } = getTextAfterCode(model.createRange(model.createPositionAt(block, 0), focus), model);
        const testOutput = testCallback(text);
        const rangesToFormat = testOutputToRanges(range.start, testOutput.format, model);
        const rangesToRemove = testOutputToRanges(range.start, testOutput.remove, model);
        if (!(rangesToFormat.length && rangesToRemove.length)) {
            return;
        }
        // Use enqueueChange to create new batch to separate typing batch from the auto-format changes.
        model.enqueueChange(writer => {
            // Apply format.
            const hasChanged = formatCallback(writer, rangesToFormat);
            // Strict check on `false` to have backward compatibility (when callbacks were returning `undefined`).
            if (hasChanged === false) {
                return;
            }
            // Remove delimiters - use reversed order to not mix the offsets while removing.
            for (const range of rangesToRemove.reverse()) {
                writer.remove(range);
            }
            model.enqueueChange(() => {
                const deletePlugin = editor.plugins.get('Delete');
                deletePlugin.requestUndoOnBackspace();
            });
        });
    });
}
/**
 * Converts output of the test function provided to the inlineAutoformatEditing and converts it to the model ranges
 * inside provided block.
 */
function testOutputToRanges(start, arrays, model) {
    return arrays
        .filter(array => (array[0] !== undefined && array[1] !== undefined))
        .map(array => {
        return model.createRange(start.getShiftedBy(array[0]), start.getShiftedBy(array[1]));
    });
}
/**
 * Returns the last text line after the last code element from the given range.
 * It is similar to {@link module:typing/utils/getlasttextline.getLastTextLine `getLastTextLine()`},
 * but it ignores any text before the last `code`.
 */
function getTextAfterCode(range, model) {
    let start = range.start;
    const text = Array.from(range.getItems()).reduce((rangeText, node) => {
        // Trim text to a last occurrence of an inline element and update range start.
        if (!(node.is('$text') || node.is('$textProxy')) || node.getAttribute('code')) {
            start = model.createPositionAfter(node);
            return '';
        }
        return rangeText + node.data;
    }, '');
    return { text, range: model.createRange(start, range.end) };
}
